Perkins 4-108 Engine Noise

[jubi964]

Hi there,

I have a Perkins 4-108 that I had completely overhauled a few years ago. Last weekend I finally got my Seamaster in the water and started the engine.
The engine itself runs great however there is a "clanging" coming from the engine that I don't like.

People have suggested that it is just a diesel knock but I'm not so sure so if anybody on here has any information it would be much appreciated.

The clanging speeds up and down with the engine revs and while constantly there is not consistent. There is a little smoke from the engine as well(very little) and it has done 1390 hours.

Thanks in advance for any help!

[zeehag]

mine smokes as well-- only under high rpms. mine is noisey-- first i had an air knock-- was fixed while underway--a leak in lift pump...... had a low oil knock-- fixed that--- made the oil leak go away. now is just a noisey old perkins with a lot of guts and heart. 1390 hours is nothing. is an old tractor-- will run forever as long as ye keep oil in it and air out of fuel system...

[SkiprJohn]

I don't like the idea of a clangy noise either. When its running can you isolate where the noise is coming from? A stethoscope or a long handled screwdriver with the handle next to your ear can get you close to where the noise is from. Be careful about belts and spinning parts when you are in the engine compartment.

Perkins engines knock and tap but normally don't clang.

kind regards,

[Unicorn Dreams]

Welc.ome Aboard Cruisers Forum

Don't take a chance. Have a mechanic come out and take a listen just in case

[shakey doug]

If you could be a bit more specific as to the location and if the noise comes and goes during rev changes. Does the noise continue in & out of gear? Please list work carried out during over haul & all parts renewed from Gbox coupling to crank pulley,previous engine history,need for overhaul etc.

[Sam Plan B]

Yes. Have a mechanic come and look. I would suspect that a bolt has come adrift where the connecting rod is coupled to the drive shaft. The lower C casting that wraps around the bottom of the drive shaft is clanging against the side of the drive shaft as it rotates. Hence the increased rate of clanging as the engine rev's up. Don't run the engine until you have it checked out.

[jubi964]

Hi, Thanks a lot for all the replies so far. I should mention that the engine is actually a 4-107, my apologies.

As per shakey doug, The reason for the overhaul was that I was doing all the woodwork and fibreglass and thought it made sense to get it done. It included new pistons, conrod, gaskets, ring sets, oil pump, water pump, cylinder head and then strip down and clean everything. Noise continues in and out of gear.

There's a guy in the boat yard that works on boats, he hooked the engine back up for me and did all the wiring and he has suggested that the clanging might be caused by a stuck injector. I rang the guys who did the rebuild and their first guess was that an injector was sticking as well so for now I'm gonna remove them all and take them for testing.

As per Sam Plan B good suggestion but thankfully that is all nice and tight and not the issue.
Its hard to isolate the noise, but would guess from the front of the block, near injector 4.

Thanks again for the help so far, I'll keep you posted.

[SkiprJohn]

4-107 is a great engine and once you get rid of the clang it'll give you good service.
kind regards,

[jubi964]

Hi there, just thought I'd let you know how things worked out. My injectors were returned to the engine rebuilder and after testing them one was faulty. This in turn was causing the clang as the piston was not being fired properly.

Thanks to all for the help, the engine sounds wonderful now, very sweet!

[zeehag]

i love how these purrty blue engines sound when in good shape

[billyocean]

Perkin engines do not clang. They knock. A clang suggests damper plate. Is there any difference in noise between idle and engaged?

[zeehag]

damper plate, air in cylinders.... not enough fuel to engine--all make a noise.
and there is also normal perkins running noise-- they aint silent. each variation o0f the normal song is something different to address..i LOVE mine!!!!

[SkiprJohn]

I know a lot of people might disagree with me but I think they were the best even though they might leak a bit and are "old school" they never let me down.
kind regards,

[zeehag]

perkins 4-108 and my yannie are the bestest....